EURO
QUARTZ
Low Profile Miniature Crystal
FEATURES
Extensional mode resonator, 760kHz to 1.35MHz
Designed for low power applications
Ideal microprocessor clock crystal
Low ageing
Full military testing available
CX-2 CRYSTAL
760kHz to 1.35MHz
OUTLINE & DIMENSIONS
DESCRIPTION
CX-2 crystals consist of a high quality extensional mode resonator in
a rugged, hermetically sealed ceramic package. The crystal is ideal
for use in battery-powered applications.
SPECIFICATION
Specifications stated are typical at 25°C unless otherwise indicated.
Specifications may change without notice.
Frequency Range:
760.0kHz to 1.35MHz
Functional Mode:
Extensional
Standard Calibration Tolerance*: A: ±0.05% (±500ppm)
B: ±0.1%
C: ±1.0%
Load Capacitance:
7pF
Motional Resistance (R1):
5kΩ maximum
Motional Capacitance (C1):
1.2fF
Quality Factor (Q):
150k
Shunt Capacitance (C0):
1.0pF
Drive Level:
3µW maximum
Turning Point (T0**):
35°C
Temperature Coefficient (k):
-0.035ppm/°C
2
Ageing First Year:
±5ppm maximum
Shock, Survival:
1000g peak, 0.3ms, ½ sine
Vibration, Survival:
10g rms, 20~1000Hz random
Operating Temperature Range:
-10°C to +70°C (Commercial)
-40°C to +85°C (Industrial)
-55°C to +125°C (Military)
Storage Temperature Range:
-55° to +125°C
Maximum Process Temperature:
See package handling note
*
**
Tighter frequency calibration is available.
Other turning point is available.
Turning Point Temperature
Note: Frequency f at temperature T is related to frequency Fo at
turning point temperature To by:
f-fo
=k(T-To)
2
fo
PACKAGING
CX-2 crystals are tray packed as standard
HOW TO ORDER CX-2 CRYSTALS
CX-2 - S
-
02 -
Leads
02
03
04
1.0MHz,
Frequency
K = kHz
A
Calibration
Tolerance
@25°C
A
B
C
/
I
Temp. Range
C = -10° ~ +70°C
I = -40° ~ +85°C
M = -55° ~ +125°C
S = Customer specified
'S' if special,
custom design.
Otherwise leave
blank
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk www.euroquartz.co.uk
EURO
QUARTZ
Low Profile Miniature Crystal
CRYSTAL EQUIVALENT CIRCUIT
CX-2 CRYSTAL
760kHz to 1.35MHz
TYPICAL APPLICATION FOR A
PIERCE OSCILLATOR
The low profile CX miniature crystal is ideal for use in small, high
density, battery operated portable products. The CX crystal designed
in a Pierce oscillator (single inverter) circuit provides very low current
consumption and high stability. A conventional Pierce oscillator is
shown above. The crystal is effectively inductive and in a Pi network
circuit with C
D
and C
G
provides the additional phase shift to sustain
oscillation. The oscillation frequency (f
O
) is 15 to 250ppm above the
crystal's resonant frequency (f
S
).
Drive Level
R
A
is used to limit the crystal's drive level by forming a voltage divider
between R
A
and C
D
. R
A
also stabilizes the oscillator against changes in
the amplifier's output resistance (R
O
). R
A
should be increased for
higher voltage operation.
Load Capacitance
The CX crystal calibration tolerance is influenced by the effective
circuit capacitances, specified as the load capacitance (C
L
). C
L
is
approximately equal to:
C
L
=
C
D
x C
G
C
D
+ C
G
+ C
S
R1 Motional Resistance
C1 Motional Capacitance
L1 Motional Inductance
C0 Shunt Capacitance
CONVENTIONAL CMOS PIERCE OSCILLATOR CIRCUIT
Note: C
D
and C
G
include stray layout-induced capacitance to ground
and C
S
is the stray shunt capacitance between the crystal terminal. In
practice, the effective value of C
L
will be less than that calculated from
C
D
, C
G
and C
S
values because of the effect of the amplifier output
resistance. C
S
should be minimized.
PACKAGE HANDLING
The CX crystal is hermetically sealed in a ceramic package. Normal
handling and soldering precautions for small, low thermal mass parts
are adequate when installing or testing CX crystals. CX crystals may
be wave soldered with proper precaution taken to avoid desoldering
the leads. A slow machine rate or too high a pre-heat temperature or
solder bath temperature may damage the crystals.
Lead to package
solder interface temperature should not exceed 175°C, glass lid
to package seal rim temperature should not exceed 210°C.
If
the seal rim reaches temperatures above the maximum specified, the
package may lose its hermeticity. Loss of hermeticity results in a
frequency decrease and motional resistance increase.
The oscillation frequency (f
O
) is approximately equal to:
C
1
2(C
O
+ C
L
)
f
O
= f
S
Where
1+
F
S
= Series resonant frequency of the crystal
C
1
= Motional Capacitance
C
O
= Shunt Capacitance
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk www.euroquartz.co.uk
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